High heat tolerance, evaporative cooling, and stomatal decoupling regulate canopy temperature and their safety margins in three European oak species

Global Change Biology, Journal Year: 2024, Volume and Issue: 30(8)

Published: Aug. 1, 2024

Abstract Heatwaves and soil droughts are increasing in frequency intensity, leading many tree species to exceed their thermal thresholds, driving wide‐scale forest mortality. Therefore, investigating heat tolerance canopy temperature regulation mechanisms is essential understanding predicting vulnerability hot droughts. We measured the diurnal seasonal variation leaf water potential (Ψ), gas exchange (photosynthesis A net stomatal conductance g s ), ( T can (leaf critical crit safety margins TSM, i.e., difference between maximum ) three oak forests along a latitudinal gradient Quercus petraea Switzerland, ilex France, coccifera Spain) throughout growing season. Gas Ψ of all were strongly reduced by increased air drying, resulting closure inhibition photosynthesis Q. when surpassed 30°C moisture dropped below 14%. Across seasons, was mainly above but (up 10°C > null or negative. Although trees endured extreme 42°C), positive TSM maintained during season due high (average 54.7°C) possibly decoupling (i.e., ≤0 while >0). Indeed, low (despite decreasing passed embolism thresholds. This may have prevented from rising heat. Overall, our work highlighted that behind include combination evaporative cooling, large limits, decoupling. These processes must be considered accurately predict plant damages, survival, mortality heatwaves.

Language: Английский

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Climatic and stand drivers of forest resistance to recent bark beetle disturbance in European coniferous forests

Global Change Biology, Journal Year: 2022, Volume and Issue: 28(8), P. 2830 - 2841

Published: Jan. 28, 2022

Bark beetle infestation is a major driver of tree mortality that may be critical for forest persistence under climate change and the forecasted increase extreme heat drought episodes. Under this context, environmental position host populations within species' climatic niche (central vs. marginal populations) expected to determinant in dynamics insect-host systems. Here, we analyzed recent patterns bark disturbance resistance across European coniferous forests during 2010-2018 period. We obtained attack data from successive continental-scale condition surveys on 130 plots including five trees species, characterized each species. Then, overall species-specific responses, terms induced mortality, relation distance optimum both previous events, plot characteristics. Regional revealed central, north, east Europe could at risk multivoltine found was determined by several driving factors, which varied among species responses. Particularly, affected characteristics mediated influence attack. In turn, exclusively maximum intensity duration events. Our findings highlight importance interactions suggest joint events will threaten forests, even those close their optimum.

Language: Английский

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Drought- and heatwave-associated compound extremes: A review of hotspots, variables, parameters, drivers, impacts, and analysis frameworks

Frontiers in Earth Science, Journal Year: 2023, Volume and Issue: 10

Published: Feb. 3, 2023

Droughts and heatwaves are rising concerns with regard to the frequent formation of compound or concurrent extremes (CEs), which can cause greater havoc than an individual event a higher magnitude. Recently, they have been frequently detected form CEs together other events (e.g., floods, aridity, humidity events) concurrently spatiotemporal lags. Therefore, this systematic review assesses these by reviewing following aspects: CE hotspots, events, variable combinations that CEs; analyzed parameters frequency severity); large-scale modes climate variability (CV) as drivers alongside approaches relate them impacts yield loss fire risk) impact integration from 166 screened publications. Additionally, three varied analysis frameworks summarized highlight different components drought- heatwave-associated CEs, is novelty study. The vary major assessment objectives: only (event–event), driver association (event–driver), (event–impact). According review, most reported hotspots in global studies southern Africa, Australia, South America, Southeast Asia. In regional studies, several vital Iberian Peninsula, Balkans, Mediterranean Basin) reported, some not mentioned because usually report broader regions. addition, drought heatwave; heatwave stagnation) varying combination variables, namely, temperature, precipitation, their derived indices. Thus, study presents for prospective researchers.

Language: Английский

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Future projection of climate extremes across contiguous northeast India and Bangladesh

Scientific Reports, Journal Year: 2023, Volume and Issue: 13(1)

Published: Sept. 20, 2023

Abstract In recent times, India has experienced a significant increase in the frequency and intensity of extreme weather events, particularly northeast (NEI), an area known for its rich natural resources. Despite geographic continuity NEI Bangladesh, previous studies have failed to consider their interconnectedness, resulting incomplete understanding situation. To bridge this gap, comprehensive study encompassed entire NEI, including West Bengal Bangladesh (hereafter referred as NEIB). This examined climate extremes NEIB, utilizing 12 temperature-based 8 precipitation-based indices developed by Expert Team on Climate Change Detection Indices. Analysis was performed temperature precipitation data obtained from Meteorological Department covering period 1981–2021. Additionally, projections 14 Global Models participating CMIP6 were incorporated 2015–2100, considering four different Shared Socioeconomic Pathways (SSPs) scenarios. Findings revealed that under SSP585 scenario, substantial rise 4 °C maximum temperatures 5.5 minimum end twenty-first century. Warming indices, such summer days index, indicated expected 53 days, while Warm spell index estimated approximately 2 days. Heavy (R20mm) projected up with notable impact Meghalaya. While number rainy is decrease, overall magnitude anticipated remain relatively stable. Notably, Simple daily demonstrated 2.4 mm/day compared current baseline 14.4 mm/day. These changes ramifications water resources, agriculture, health, infrastructure region.

Language: Английский

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Growth of tree (Pinus sylvestris) and shrub (Amelanchier ovalis) species is constrained by drought with higher shrub sensitivity in dry sites

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 918, P. 170539 - 170539

Published: Feb. 1, 2024

We lack understanding of how variable is radial growth coexisting tree and shrub species, constrained by drought depending on site aridity. Here, we compared the two widespread a winter deciduous (Amelanchier ovalis Medik.) an evergreen conifer (Pinus sylvestris L.). sampled four sites in Northeastern Spain subjected to different aridity levels used dendrochronological methods quantify patterns responses climate variables. The species varied between regions, being lower driest sites. first-order autocorrelation (growth persistence) was higher more mesic but without clear differences species. Tree negatively responded elevated summer temperatures positively spring-summer precipitation wet conditions. However, negative were only observed contrast tree. Abrupt reductions common drier sites, resilience indices show that rapidly recovered pre-drought levels. synchrony as can be due multistemmed architecture, fast low stature shrub. Besides, high dependency rainfall explain why limitations apparent In any case, results point out potential shrubs, which particularly relevant giving its ability inhabit woodlands treeless regions under harsh climatic Nevertheless, further research required elucidate capacity tolerate drought, well understand shrubs thrive water- cold-limited environments.

Language: Английский

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Assessing the impact of multi-year droughts on German forests in the context of increased tree mortality

Ecological Modelling, Journal Year: 2024, Volume and Issue: 492, P. 110696 - 110696

Published: April 6, 2024

Forests play a crucial role in climate regulation and societal well-being. Despite their significance, the increasing frequency of droughts poses severe threat to forest ecosystems, impacting carbon sequestration stability. In Germany, unprecedented 2018–2020 drought resulted extensive tree mortality damaged wood volume, with lasting effects observed subsequent years. As models project continuation such droughts, understanding impact on forests becomes imperative. However, it is unclear how will evolve future if duration continues increase. This study employs model analyze across various German types, focusing periods influence productivity. By utilizing an individual-based growth national inventories, addresses critical knowledge gaps regarding multi-year biomass productivity including monocultures mixed forests. The simulations consider drought-induced large increase caused by factors as pest infestations diseases Germany. Our simulation results reveal declining aboveground gross primary production (GPP) for all simulated scenarios, three- six-year drought. GPP reduced 46 % 3-year scenario 58 6-year scenario. Notably, prolonged lead cumulative losses, saturation effect scenarios exceeding eight Forest stand composition influences these impacts, greater losses low-biomass stands. Furthermore, different types exhibit varying responses. Monocultures even-sized (mostly planted managed forests) are more sensitive than uneven-sized provide valuable insights into resilience ecosystem responses increasingly frequent highlighting importance inform management strategies. Modelling biotic dynamics process-based manner remains challenge that requires research.

Language: Английский

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Detecting the human fingerprint in the summer 2022 western–central European soil drought

Earth System Dynamics, Journal Year: 2024, Volume and Issue: 15(1), P. 131 - 154

Published: Feb. 16, 2024

Abstract. In the 2022 summer, western–central Europe and several other regions in northern extratropics experienced substantial soil moisture deficits wake of precipitation shortages elevated temperatures. Much has not witnessed a more severe drought since at least mid-20th century, raising question whether this is manifestation our warming climate. Here, we employ well-established statistical approach to attribute low summer human-induced climate change using observation-driven estimates models. We find that Europe, June–August root zone such as expected occur once 20 years present but would have occurred only about per century during preindustrial times. The entire show an even stronger global imprint with 20-fold probability increase or higher, note underlying uncertainty large. Reasons are manifold include lack direct observations required spatiotemporal scales, limitations remotely sensed estimates, resulting need simulate land surface models driven by meteorological data. Nevertheless, observation-based products indicate long-term declining for both regions, tendency likely fueled regional warming, while no clear trends emerge precipitation. Finally, model analysis suggests under 2 ∘C 2022-like conditions become twice compared today take place nearly every year across extratropics.

Language: Английский

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Drought responses of Italian silver fir provenances in a climate change perspective

Dendrochronologia, Journal Year: 2024, Volume and Issue: 85, P. 126184 - 126184

Published: Feb. 29, 2024

In a climate change perspective, the resilience of Mediterranean forest ecosystems is closely linked to their ability cope with drought and rising temperatures. This can be influenced by genetic differences between within species or provenances. changing environment, management guidelines should weight risks associated both local and/or non-local provenances, promote effective conservation sustainable resilient resources. this study, we analysed growth responses silver fir (Abies alba) in Tuscan-Emilian Apennine National Park natural planted forests, comparing performance three provenances Italy: (a) Western Alpine - (b) Northern (local) (c) Southern Apennine. Drought severity was defined Standardised Precipitation-Evapotranspiration Index (SPEI). We carried out dendrochronological analyses assessing climate-growth relationships applying 'resilience indices' (RRR) based on tree ring width. Planted forests showed faster mean than highly fragmented higher severe significantly recovery drought. Fir do not differ rate, while provenance better (rec) (resl) especially compared during moderate (rec +5-15%, resl +13-15%) extreme +20% %, +22%) years. The an intermediate behaviour. one, proving very important resources context response strategies. Finally, RRR indices trends calculated years identified SPEI6 generally greater regeneration modes SPEI12, possibly due increase recurrent short-duration droughts mountainous contexts growing season. These results provide information different under change, highlighting importance taking into account background reproductive materials planning. Thanks close collaboration managers, these may find concrete application, e.g., properly evaluating usefulness assisted migration providing remnant forests.

Language: Английский

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Drought priming improves tolerance of Alhagi sparsifolia to subsequent drought: A coordinated interplay of phytohormones, osmolytes, and antioxidant potential

Plant Stress, Journal Year: 2024, Volume and Issue: 12, P. 100469 - 100469

Published: April 25, 2024

Perennial trees are often stressed by drought more than once during their life cycle. Our study exposed three-month-old Alhagisparsifolia, with (drought-primed) or without (nonprimed) prior stress to subsequent for two months, aiming reveal whether pre-exposure could enhance seedling resistance and investigated possible underlying mechanisms. Root biomass, leaf relative water content, chlorophyll a, carotenoids were significantly higher in drought-primed nonprimed seedlings. They also had reduced concentrations of malondialdehyde, hydrogen peroxide (H2O2), superoxide anions (O2•−), indicating relief from oxidative stress. This was associated a coordinated upregulation enzymes scavenging O2•− H2O2, particularly dismutase (SOD) catalase (CAT), the maintenance ascorbate-glutathione (AsA-GSH) redox pool enzymatic activities (ascorbate peroxidase, mono- dehydroascorbate reductase, glutathione reductase), leading better regulation reactive oxygen species. The failure seedlings upregulate SOD, CAT, AsA-GSH cycles nevertheless made susceptible increased levels strigolactones, jasmonic acid, abscisic acid roles displayed gibberellic indole acetic acid. A principal component analysis showed that responded differently if they previously suffered drought, mainly due capacity pigment protection, scavenging, osmolytes, anti-stress hormones. provides insights into benefits memory induced early priming as strategy overcoming

Language: Английский

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South America is becoming warmer, drier, and more flammable

Communications Earth & Environment, Journal Year: 2024, Volume and Issue: 5(1)

Published: Sept. 26, 2024

Language: Английский

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